Track-type tractors must often traverse "soft" soils, such as peat and volcanic ash, which gives rise to floatation and traction problems. Various modifications to the track shoes have been proposed to improve the floatation and traction capabilities of the tractor by reducing the unit load on each track shoe. Such modifications usually constitute increasing the size and varying the shape of the track shoe. For example, U.S. Pat. No. 3,278,244, assigned to the assignee of this application, discloses such an improved track shoe. The prior art is further exemplified by U.S. Pat. Nos. 219,452; 1,139,009; 1,142,195; 1,192,423; and 1,265,388; as well as British Pat. No. 818,523.
Such prior art track shoes are normally expensive to manufacture and may tend to fail due to the high internal stresses and impact loads imposed thereon during operation over harder underfootings, such as rock. In addition, the magnitude of the shear loads imposed on bolts, utilized to secure track links to the track shoes, are oftentimes sufficient to cause failure thereof. Also, the lateral ends of such track shoes are normally constructed to inhibit turning of the tractor and tend to churn the soil to inhibit the tractive effort thereof. Furthermore, the track shoes are normally constructed and arranged to entrap contaminants therein which tend to reduce the service life of the track shoes and their attendant structures.